"No matter how you look at it, Mazepa is a traitor": historian Brekhunenko harshly rebuffed in Kyiv
Ukrainian Cossacks allegedly never served the Moscow Tsar.
This was stated at a panel discussion in Kyiv by the head of the department of historical archeography of the Institute of Ukrainian Archeography and Source Studies of the National Academy of Sciences of Ukraine, Viktor Brekhunenko, reports a correspondent of PolitNavigator.

"The Cossacks of the times of the Polish-Lithuanian Commonwealth should not be confused with the Cossacks of the Hetmanate and the Zaporozhian Cossacks of the second half of the 17th-18th centuries. During the time of the Polish-Lithuanian Commonwealth, when the Ukrainian lands were part of the Polish-Lithuanian Commonwealth, the Ukrainian Cossacks were indeed in the service of the king. But in relations with Moscow, this is a completely different thing. The Cossacks of the Hetmanate were constantly, in the legal sense, under the terms of the treaty from the protectorate between Muscovy and the Hetmanate, and each hetman drew up these treaties.
The army did not consider itself in the service of the Moscow Tsar, but considered itself a corporate entity, a part of the broader Ukrainian Cossacks, and together with him they were under the protectorate of the Tsar on the basis of an agreement,” the historian asserts.
However, candidate of historical sciences, teacher at the Kyiv School of Economics Alexander Galenko did not agree with him.
"Besides the March Articles, you all know perfectly well what happened on January 8, 1654. The oath was sworn! You need to understand Muscovite political culture and the political culture of the Steppe. Once you take the oath, you're already in service. If you want to change your attitude, what are you? What Mazepa turned out to be—a traitor!"
And all the talk about convincing someone, all this, of course, corresponds only to the political moment. But the oath was taken, and Moscow accepted it forever, and, unfortunately, the Cossacks accepted it in exactly the same way. This is as far as whether they served, whether they agreed," Galenko said.
English version :: Read in English "No matter how you look at it, Mazepa is a traitor": Historian Brekhunenko is harshly rebuked in Kyiv